「Cardraptor," a card game that mixes digital and analog elements, became an unprecedented global hit through its media mix (novels, anime, etc.), and has reigned as the world's top card game for 25 years.

Yamashiro Tenma, the assistant manager of a card shop and a certified Cardworth judge, was on his way home, carrying a large number of pre-constructed decks for sale and his own tournament decks due to store renovations, when he suddenly found himself transported to a medieval-style world.

In this extraordinary world, Cardraptor cards have materialized and are utilized in every aspect of life: military, politics, and commerce, with their value as assets guaranteed.

Tenma then realizes that this world only has cards up to Season 6. He also discovers that most of the summoning methods for cards with special summoning conditions have been lost.

This is the story of Tenma, who, while everyone else around him uses cards up to Season 6, finds himself with over 40 meta decks from Season 11. He desperately tries to survive, selling off cards and information to various factions and individuals, all to secure his place and safety in this other world.

Also simultaneously posted on Shosetsuka ni Narou, Kakuyomu, and Hameln.